Installation guide

Glossary
Manual No. 775007 G-7
SCSI
SCSI is an acronym for “Small Computer Systems Interface,” although it is
often used in large systems. The SCSI interface supports disk drives, tape
drives, and CDROM drives. Narrow SCSI supports up to 7 devices on a
channel, and Wide SCSI, Ultra SCSI, and Ultra2 SCSI support up to 15
devices on a channel.
SCSI Drive
A disk drive equipped with a SCSI interface (sometimes referred to as a
SCSI Disk). Each disk drive will be assigned a SCSI address (or SCSI ID),
which is a number from 0 to 7 (0 to 15 under wide or Ultra SCSI). The SCSI
address uniquely identifies the drive on the SCSI bus or channel.
SCSI Drive States
Refers to a SCSI drive’s current operational status. At any given time, a SCSI
drive can be in one of five states: READY, ONLINE, STANDBY, DEAD, or
REBUILD.
The controller stores the state of the attached SCSI drives in its non-volatile
memory. This information is retained even after power-off. Hence, if a SCSI
disk is labeled DEAD in one session, it will stay in the DEAD state until a
change is made either by using a system level utility or after a rebuild. Each
of the states is described below:
Ready: A SCSI disk drive is in a “ready” state if it...
Is powered on; and
Is available to be configured during the current session but remains
unconfigured.
Online: A SCSI disk drive is in an “online” state if it...
Is powered on; and
Has been defined as a member of a drive group; and
Is operating properly.